Regulation of work hours for physicians in training was put in place by the Accreditation Council for Graduate Medical Education (ACGME) in 2003, long after similar regulations were implemented in trucking, aviation, and in other occupations where acute and chronic sleep deprivation raise significant concerns about safety. The impact of duty hour regulation has been controversial. While there is some evidence that this improved mortality outcomes in the short-term, little is known about the impact on educational outcomes, longer-term clinical outcomes, or the mechanisms creating inter-hospital differences in the effectiveness of duty hour reform in improving either clinical or educational outcomes. With assistance from the American Board of Surgery, the American Board of Internal Medicine, the National Board of Medical Examiners, the Association of Program Directors in Internal Medicine and Surgery, and the American College of Physicians, we propose to complete the following specific aims: 1. To describe the variety and frequency of program-level behavioral responses to duty hour reform and resident work conditions by conducting national surveys of program directors and residents in Internal Medicine (IM) and General Surgery (GS) informed by qualitative field work at a sample of IM and GS residency programs. 2. To assess how educational outcomes (board scores) have changed over time in conjunction with duty hour reform for residents in different specialties. 3. To examine how clinical outcomes (mortality, failure-to-rescue, probability of a prolonged length of stay, patient safety indicators) have changed over time beyond the first two years post-duty hour reform. 4. To examine the relationship between changes in educational and clinical outcomes and hospital financial performance, physician extender and nurse staffing levels, and program responses identified in the national survey of program directors. The proposed analysis will be the first to pull together national data on educational and clinical outcomes and will help us understand why duty hour regulation reform for physicians in training worked - or did not work - in terms of improving educational and clinical outcomes. This is an important policy question given that the physicians who are the subject of these reforms provide care to tens of millions of Americans each year. PUBLIC HEALTH RELEVANCE Regulation of duty hours for physicians in training in 2003 represented one of the most significant efforts ever undertaken to improve patient safety in American hospitals. It is largely unknown how these regulations affected patient outcomes, the quality of physician training, and how programs responded to improve or maintain patient outcomes and the quality of residency training. In this study, we will examine how residency programs and hospitals responded to the duty hour reform and how these behavioral responses determined which residency programs and hospitals experienced relative improvements or worsening in educational and clinical outcomes, important questions given that tens of millions of Americans receive care from the physicians in training who were the subject of the duty hour regulation.